/* Copyright (c) 2014, 2021, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/*
  Bug#16403708 SUBOPTIMAL CODE IN MY_STRNXFRM_SIMPLE()
  Bug#68476    Suboptimal code in my_strnxfrm_simple()

  Below we test some alternative implementations for my_strnxfrm_simple.
  In order to do benchmarking, configure in optimized mode, and
  generate a separate executable for this file:
    cmake -DMERGE_UNITTESTS=0
  You may want to tweak some constants below:
   - experiment with num_iterations
  run './strings_strnxfrm-t --disable-tap-output'
    to see timing reports for your platform.


  Benchmarking with gcc and clang indicates that:

  There is insignificant difference between my_strnxfrm_simple and strnxfrm_new
  when src != dst

  my_strnxfrm_simple() is significantly faster than strnxfrm_new
  when src == dst, especially for long strings.

  Loop unrolling gives significant speedup for large strings.
 */

// First include (the generated) my_config.h, to get correct platform defines.
#include "my_config.h"
#include <gtest/gtest.h>
#include <vector>

#include "strnxfrm.h"

namespace strnxfrm_unittest {

#if defined(GTEST_HAS_PARAM_TEST)

#if !defined(NDEBUG)
// There is no point in benchmarking anything in debug mode.
const size_t num_iterations= 1ULL;
#else
// Set this so that each test case takes a few seconds.
// And set it back to a small value before pushing!!
// const size_t num_iterations= 20000000ULL;
const size_t num_iterations= 2ULL;
#endif

class StrnxfrmTest : public ::testing::TestWithParam<size_t>
{
protected:
  virtual void SetUp()
  {
    m_length= GetParam();
    m_src.assign(m_length, 0x20);
    m_dst.assign(m_length, 0x20);
  }
  std::vector<uchar> m_src;
  std::vector<uchar> m_dst;
  size_t m_length;
};

size_t test_values[]= {1, 10, 100, 1000};

INSTANTIATE_TEST_CASE_P(Strnxfrm, StrnxfrmTest,
                        ::testing::ValuesIn(test_values));

TEST_P(StrnxfrmTest, OriginalSrcDst)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_orig(&my_charset_latin1,
                  &m_dst[0], m_length, m_length,
                  &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, OriginalUnrolledSrcDst)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_orig_unrolled(&my_charset_latin1,
                           &m_dst[0], m_length, m_length,
                           &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, ModifiedSrcDst)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_new(&my_charset_latin1,
                 &m_dst[0], m_length, m_length,
                 &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, ModifiedUnrolledSrcDst)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_new_unrolled(&my_charset_latin1,
                          &m_dst[0], m_length, m_length,
                          &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, OriginalSrcSrc)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_orig(&my_charset_latin1,
                  &m_src[0], m_length, m_length,
                  &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, OriginalUnrolledSrcSrc)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_orig_unrolled(&my_charset_latin1,
                           &m_src[0], m_length, m_length,
                           &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, ModifiedSrcSrc)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_new(&my_charset_latin1,
                 &m_src[0], m_length, m_length,
                 &m_src[0], m_length, 192);
}

TEST_P(StrnxfrmTest, ModifiedUnrolledSrcSrc)
{
  for (size_t ix= 0; ix < num_iterations; ++ix)
    strnxfrm_new_unrolled(&my_charset_latin1,
                          &m_src[0], m_length, m_length,
                          &m_src[0], m_length, 192);
}

#endif  // GTEST_HAS_PARAM_TEST

}
